Discharge tube arrangement



1942- W. KLEEN 2,268,835

bIscHAizGE TUBB'ARRANGE'MENT Filed Aug. 10, 1939 INVENTOR. WERNER LEEN ATTORNEY.

Patented Jan. 6, 1942 v 2,268,830 DISCHARGE TUBE ARRANGEMENT Werner Klecn, Berlin, Germany, assignor to'Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporation of Germany Application August10, 1939, Serial No. 289,372

4 Claims.

lhe invention resides in a multiplicatively operating mixer tube arrangement with negative input resistance on both control grids.

In U. S. patent application Serial No. 202,186, filed April 15, 1938, by H. Rothe and entitled Mixing tube circuit arrangement, a mixer arrangement is described in which a control grid for the current distribution, more especially the third grid, of a multi-grid tube has a negative input resistance owing to influence phenomena and the said control grid excites an oscillatory circuit connected thereto and tuned to the cally produced frequency, while the first grid has the receiving oscillations applied thereto.

In accordance with the present invention a negative resistance is produced through influence at the input control grid as well as at the local frequency control grid of a mixer tube. This is possible in view of the fact that the first control grid is not in the direct vicinity of the cathode but is'separated therefrom by a grid maintained at positive potential and acting so to say as space charge grid or as acceleration electrode. These two grids bring about a control by current distribution whose characteristic condition is a negative input resistance (see Telefunken Rohre Journal 9, page 55 and following).

An example of construction according to the invention is shown in the accompanying drawing in which the oscillatory circuits are designated by the frequencies appertaining to them. The cathode K of the five grid tube R is followed by the auxiliary grid I having a positive direct potential of generally about 10 volts. There is arranged in back of said auxiliary grid the input control grid 2 to which the input frequency h is Germany August 26, 1938 this causes the circuit tuned to the local oscillagrid, i. e. to exchange the action of the grid 2 math that of 4.

Iclaim:

1. In a mixer circuit wherein incoming signal energy is combined with locally produced oscillations of a second frequency to produce an intermediate frequency, a mixer tube having a cathode, an anode and first and second grid electrodes interposd between the cathode and anode in the order named, means for providing negative conductance between the second grid and the cathode including means for maintaining the first grid electrode at a positive'potential with respect to the cathode, and means for impressing the incoming signal energy between said second grid electrode and the cathode, said negative conductance bein sufficient to cause only regeneration of the incoming energy.

2. In an arrangement as described in the next preceding claim and wherein said mixer tube is also provided with third and fourth grid else-- a third frequency, a mixer tube having a cathode, an anode and first, second, third and fourth grid electrodes interposed between the cathode and anode in the order named, means for maintaining the first grid electrode at a positive potential with respect to the cathode, means for connecting the second grid electrode to a source of negative potential, said means including a circuit resonant at said first frequency, said first gr1d acting as a space charge grid with relation to said second grid so that a negative resistance is produced between the second grid and the cathode, means for maintaining the third grid at a positive potential with respect to the cathode, means including a circuit resonant at said second frequency for connecting the fourth grid to a source of negative potential, said third grid acting as a, space charge grid between said fourth grid and. the cathode so that a negative resistance is produced between the fourth grid and the cathode, and means including a circuit resonant at said third frequency for connecting the anode to a source of positive potential.

' 4. An arrangement as described in the next preceding claim, characterized by that the first named resonant circuit is coupled to a source of 

